So is it possible to cut your travel costs by going the very long way round – and via the airport? As the following examples show, yes, it is – although a degree of forward planning is also required. All the prices quoted here are correct at time of publication. Train tickets are the cheapest available on the day for that journey, via the given operator. Plane fares are also the lowest available, not including add-ons such as checked-in bags.

1. Luton to Edinburgh (via Denmark)

By train: The lowest price available – via Virgin Trains (virgintrains.co.uk) – for a single fare from Luton to the Scottish capital on February 12 is £72 (changing at King’s Cross).

A Ryanair (ryanair.com) flight from Luton to the Danish capital on February 12 costs from £22.49. An onward service to Copenhagen with the same airline is £43.19. Total flight price: £65.68

Saving: £6.32

While you’re there: The Danish capital is an intriguing city, whose most photographed site – the waterfront statue of Hans Christian Andersen’s Little Mermaid – is free to see.

Copenhagen: intriguing Photo: GETTY

2. Newquay to Glasgow (via Spain)

By train: Tickets for a single journey between western Cornwall and Scotland’s second city on May 15 start at £225 via The Trainline (thetrainline.com). Passengers need to change at Par, Plymouth and Manchester Piccadilly.

The air alternative: Alicante

A Ryanair flight from Newquay to Alicante on the same day costs from £49.49. Onward seats on an EasyJet (easyjet.com) service from Alicante to Glasgow cost from €174.99 (£133). Total flight price: £182.49

Saving: £42.51

While you’re there: Pitched on the south-east coast of Spain, Alicante is a port city with a reputation as a place for easy sun and sand. Look up, though, and you can also enjoy a dash of history – via the epic Castillo de Santa Barbara, which crowns Mount Benacantil.

Alicante: sun and sand Photo: AP/FOTOLIA

3. Cardiff to Newcastle (via Mallorca)

By train: Catch the 9:55am from the Welsh capital to Newcastle-on-Tyne on April 23 (changing at Bristol Parkway), and you can expect to pay from £153.50 at The Trainline.

You can fly from Cardiff to the Mallorcan capital on the same day from €49.99 (£37.97) – via Vueling (vueling.com). A Jet2 (jet2.com) connection to Tyneside on the same day costs from €99 (£75.18). Total flight price: £113.15

Saving: £40.35

While you’re there: The biggest city in the Balearic Islands is a feast of sunshine and sparkle – where elegant art gallery Es Baluard (esbaluard.org) has works by Joan Miro.

Flying often trumps the train when it comes to price Photo: GETTY

4. Southampton to Glasgow (via Ireland)

By train: Travel on April 1 and you can flit from Southampton to Glasgow (changing in Wolverhampton) from £145.40 via Virgin Trains East Coast (virgintrainseastcoast.com).

The air alternative: Cork

Aer Lingus (aerlingus.com) offers a multi-city option which lets you book a flight from Southampton to Cork on April 1 for £25.68 – and an onward hop from Cork to Glasgow later that day from £35.99. Total flight price: £61.67

Saving: £83.83

While you’re there: Often caught in Dublin’s shadow, Cork is nonetheless a pretty city where St Finbarre’s Cathedral (corkcathedral.webs.com) is a 19th century neo-Gothic joy.

27 reasons trains are better than planes

As illustrated above, they can sometimes be costly. But a poll of 22,000 people last year suggested that most prefer to take the train. Here's why